the american civil liberties union over police use of the high-tech tool. tool. keith daniels, ... here.../ with... why... the... ac---lu... believes... "tag-readers" ... could be ...an invasion ... of... privacy.. keith. /////////////////////keith////// //////// 3 ///////////////////////keith//// ////////////// jennifer.... the a-c-l-u has sent out a public records request to nearly 30 law enforcement agenices.. including balitmore city and county police. bottom line, they want to know how the cameras are being used.. and most importantly, what's happening to the data. //////////////////////vo//////// ////////////// here's how the system cameras, which are usually mounted on patrol cars, scan every license plate on passing or parked vehicles.. and run the numbers through police data bases. baltimore county police call the "tag-readers" a very useful law enforcement tool that can, among other things, help find stolen cars. but the a-c-l-u says the data gathered is stored indefinitely.. and could potentially be an invasion of privacy.